Declining budgets are causing U.S. forces to drastically reduce manpower and resources. To offset these reductions, the military has turned to high technology as a force multiplier. Electronic sensors are a key force multiplier, and one type of sensor for tactical aircraft, fire-control radar, has proven to be a crucial element in establishing air superiority over potential adversaries in war. This paper discusses the advantages, history, and enabling technologies of a superior and emerging technology for fire-control radars. Active-element phased-array radar, while costly to develop and produce, offers dramatic improvements in performance over mechanical-scan radar, and it is also more reliable and maintainable. Two technologies, digital signal processors and gallium arsenide monolithic microwave integrated circuits (MMICs), have enabled the development of efficient and affordable active phased arrays, but the high production cost of MMIC transmit/receive modules continues to be a problem and stands as the final obstacle to more widespread use of active arrays in deployed systems.